RESUMEN
PURPOSE: To evaluate the histopathological characteristics of clinically advanced retinoblastoma (RB) and its relationship with tumor differentiation. METHODS: This was a cross-sectional study of primary enucleated group D/E intraocular RB using medical records from 2017 to 2020 in a tertiary referral hospital. Cases with incomplete histopathological results were excluded. Tumors were classified into well, moderately, and poorly differentiated and undifferentiated. High-risk histopathological features were classified as per Thaung and Karaa [Community Eye Health. 2018;31(101):17-3]. RESULTS: This study included 121 patients (129 eyes), of which 32.2% were diagnosed at 25-36 months. High-risk features (HRFs) were found in 100/129 eyes, and of 73 complete histopathological results, the 2 most common HRFs were postlaminar optic nerve invasion and massive choroidal invasion. RB was poorly differentiated in 69.9% and well differentiated in 12.3% of eyes. There was no statistically significant association between any HRFs and tumor differentiation, with age >2 years associated with tumor differentiation (p < 0.05). CONCLUSION: The frequency of HRFs is 77.5% of primary enucleated eyes, mainly poorly and undifferentiated cells, particularly in children aged >2 years old.
